Balancer for washing machine and method of manufacturing the same

Abstract

A balancer for a washing machine includes a housing into which a fluid is injected, in which the housing is integrally formed by blow molding.

What is claimed is: 
     
         1 . A balancer for a washing machine, the balancer coupled to a rotary tub of the washing machine, the balancer comprising:
 a housing into which a fluid is injected,   wherein the housing is integrally formed by blow molding.   
     
     
         2 . The balancer of  claim 1 , further comprising:
 at least one inlet which is formed in a surface of the housing; and   a sealing cap which seals the inlet,   wherein the sealing cap is inserted into the inlet and fused with the inlet.   
     
     
         3 . The balancer of  claim 2 , wherein the inlet is also a passage for air that is injected into the housing when the blow molding of the housing is performed. 
     
     
         4 . The balancer of  claim 1 , further comprising:
 a plurality of coupling members along a circumference of the housing, having coupling holes formed therein for coupling the housing to the rotary tub,   wherein the blow molding of the housing is performed after the plurality of coupling members is inserted into the mold for blow molding.   
     
     
         5 . A method of manufacturing a balancer for a washing machine, the balancer coupled to a rotary tub of the washing machine, the method comprising:
 integrally forming, by blow molding, a housing into which a fluid is injected inside the balancer.   
     
     
         6 . The method of  claim 5 , further comprising:
 injecting the fluid into the balancer through at least one inlet formed in a surface of the housing;   inserting a sealing cap into the inlet; and   fusing the sealing cap with the inlet.   
     
     
         7 . The method of  claim 6 , wherein the inlet is also a passage for air that is injected into the housing in the blow molding step. 
     
     
         8 . The method of  claim 5 , further comprising:
 inserting a plurality of coupling members into a mold for blow molding prior to the blow molding step,   wherein the coupling members are provided along a circumference of the housing, and have coupling holes formed therein for coupling the housing to the rotary tub.   
     
     
         9 . A method of manufacturing a balancer for a washing machine, the method comprising:
 inserting a plurality of coupling members into a mold at the circumference of the mold; and   after inserting the coupling members into the mold, using blow molding to form a housing for the balancer as a single piece that conforms to the mold and that integrally incorporates the coupling members.   
     
     
         10 . The method of  claim 9 , further comprising:
 after the blow molding is completed, injecting a fluid into the balancer through an inlet in the housing.   
     
     
         11 . The method of  claim 10 , further comprising:
 inserting a sealing cap into the inlet; and   fusing the sealing cap with the inlet to seal the inlet.   
     
     
         12 . The method of  claim 10 , wherein the inlet is also a passage for air that is injected into the housing in the blow molding. 
     
     
         13 . A washing machine comprising the balancer of  claim 9 , the washing machine further comprising a rotary tub coupled to the balancer via members inserted into holes in the coupling members.